EP0254300A2 - System zur Erzeugung von gedrehten Graphikmustern - Google Patents

System zur Erzeugung von gedrehten Graphikmustern Download PDF

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Publication number
EP0254300A2
EP0254300A2 EP87110628A EP87110628A EP0254300A2 EP 0254300 A2 EP0254300 A2 EP 0254300A2 EP 87110628 A EP87110628 A EP 87110628A EP 87110628 A EP87110628 A EP 87110628A EP 0254300 A2 EP0254300 A2 EP 0254300A2
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EP
European Patent Office
Prior art keywords
dot
coordinate
transformed
destination
straight line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP87110628A
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English (en)
French (fr)
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EP0254300A3 (de
Inventor
Ryuji C/O Nec Corporation Horiguchi
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NEC Corp
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NEC Corp
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Application filed by NEC Corp filed Critical NEC Corp
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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T3/00—Geometric image transformations in the plane of the image
    • G06T3/60—Rotation of whole images or parts thereof
    • G06T3/606—Rotation of whole images or parts thereof by memory addressing or mapping

Definitions

  • the present invention relates in general to graphic display technique, and more specifically to a rotated graphic pattern generating system for rotating a graphic pattern stored in a display memory so that a rotated graphic pattern can be displayed.
  • a first method includes an individual coordinate transformation of a required rotational angle ⁇ of respective dots included in a source graphic pattern on a dot by dot basis. All of this processing is executed on the program-basis.
  • a second method uses a X-direction straight line generator and a Y-direction straight line generator.
  • the X-­direction straight line generator is used to rotate one line of X direction included in a source graphic pattern to be rotated
  • the Y-direction straight line generator is used to rotate a left side of the source graphic pattern to be rotated, i.e., a reference point (or a leading point) of each line of the X direction.
  • These generators are used in combination to convert respective dots included in the source graphic pattern in an incremental manner starting from the reference point.
  • the first method needs a large amount of calculation of trigonometric functions, because the coordinate transformation must be performed for each dot by using the trigonometric functions. Therefore, a long calculation time is inevitably required, and a large amount of hardware must be installed.
  • the second method is free from the above mentioned defect of the first method, because the coordinate transformation can be obtained from only repeated addition and subtraction based on a straight line generation algorithm.
  • Figure lA illustrates one example of dot distribution included in a given rectangular pattern P on a source coordinate.
  • Figure lB illustrates a rotated straight line generated by the X-­direction straight line generator from a line L1 included in the source pattern P.
  • Figure lC illustrates a rotated pattern generated by the X-direction straight line generator and the Y-direction straight line generator in combination from the rectangular pattern P on the source coordinate shown in Figure lA.
  • the line L1 included in the rectangular pattern P on the source coordinate and in parallel to the X-axis of the source coordinate is rotated.
  • the X-­direction straight line generator is used to perform the coordinate transformation starting from the leading dot a1 (XS1, YS1) of the line L1 to the trail end dot on the same line L1 on such a dot by dot basis that after one dot is coordinate-transformed, another dot adjacent to the transformed dot is coordinate-transformed next, so that the coordinate-transformed dots are plotted on a destination coordinate.
  • the dot (XS1, YS1) on the source coordinate is transformed to a dot (XD, YD) on the destination coordinate, and a rotational angle ⁇ is less than 45 degree
  • the dot (XS1+l, YS1) adjacent to the dot (XS1, YS1) on the line L1 is transformed to
  • the position to which one dot on the source coordinate is to be coordinate-­ transformed i.e., moved is determined on the destination coordinate system, and then, the dot information on the source pattern corresponding to that dot is rewritten to the dot position determined on the destination coordinate. Thereafter, the coordinate transformation of the next dot is executed in the same manner.
  • the above mentioned processing is repeatedly performed until the drawing operation is completed over the full length DH of the line L1 in the X direction. Thereafter, the coordinate transformation is executed on the second line L2.
  • a dot position on the destination coordinate corresponding to the leading dot of the line L2 on the source coordinate is generated in the Y-­direction straight line generator.
  • the other dot positions on the destination coordinate corresponding to the second and succeeding dots of the line L2 are produced by the X-direction straight line generator, so that a rotated pattern of the second line L2 is drawn.
  • the second method as mentioned above is disadvantageous in that unredrawn portions are generated in the rotated pattern as indicated by Z1, Z2, Z3 in Figure lC.
  • the information before the rotation of the pattern remains. This is called "bugs".
  • the rotated pattern having dot lack portions in the redrawn area cannot have a natural feeling.
  • Another object of the present invention is to provide a rotated graphic pattern generating system capable of generating a rotated graphic pattern having no unredrawn portion.
  • Still another object of the present invention is to provide a rotated graphic pattern generating system which comprises only a slight additional elements in comparison with the conventional one and which can produce a rotated graphic pattern having no unredrawn portion.
  • a rotated pattern generating system which includes at least a X-direction straight line generator adapted to calculate, when there is to be determined a position on a destination coordinate of a next dot adjacent to a just before coordinate-transformed dot in the X direction on a source coordinate, a difference in X- and Y-directions between the position of the just before coordinate-transformed dot on the destination coordinate and a position of the next dot to be coordinate-transformed on the destination coordinate, which difference is determined by the difference on the source coordinate between the just before transformed dot and the next dot to be transformed and a required rotational angle 8, wherein the improvement comprises a detector connected to the X-direction straight line generator for discriminating whether or not a dot lack occurs each time the X-direction straight line generator generates an output, and a dot generator in response to the output of the detector to generate, when a dot lack is discriminated to generate, a signal which cause to
  • the position where the dot lack will occur is supplemented with the same dot information as that of the adjacent dot position in the destination coordinate. Therefore, no unredrawn portion will occur in the rotated pattern on the destination coordinate, and therefore, the rotated pattern is free from unnaturalness.
  • a rotated pattern generating system for rotating by a given rotational angle ⁇ a dot pattern information stored in a given area in a display memory, comprising: a display memory storing a dot information for a dot pattern to be rotated by a given rotational angle ⁇ ; a source coordinate register for holding a dot coordinate position in a source coordinate defining the dot pattern before the pattern rotation; a destination coordinate register for holding a dot coordinate position on a destination coordinate defining a dot pattern after the pattern rotation; a X-direction straight line generator for generating a first pair of increment signals of zero or integer for X-and Y- directions, the increment signals being respectively representative of a difference in X- and Y- directions between the destination coordinate position of the just before coordinate-transformed dot and the destination coordinate position of the next dot to be coordinate-­transformed, in accordance with the given rotational angle ⁇ and on the basis of the difference on the source coordinate between the just before coordinate
  • FIG. 2 there is shown one embodiment of the rotated pattern generating system in accordance with the present invention.
  • the shown system comprises a processing apparatus l0 adapted to perform necessary programmed calculations and programming operations and to control associated circuits.
  • the processing apparatus l0 is associated with a X-direction straight line generator l2 and a Y-direction straight line generator l4.
  • the former generator l2 is adapted to perform the following operation: When there is to be determined a position on a destination coordinate of a next dot adjacent to a reference or leading dot of a X-direction line on a source coordinate or a just before coordinate-transformed dot of a X-direction line on the source coordinate, the X-direction straight line generator l2 calculates a difference in X- and Y- directions between the destination coordinate position of the leading dot or the just before coordinate-transformed dot and the destination coordinate position of the next dot to be coordinate-transformed, in accordance with a required rotational angle ⁇ and on the basis of the difference on the source coordinate between the leading dot or the just before coordinate-transformed dot and the next dot to be coordinate-transformed.
  • the X-direction straight line generator On the basis of the difference thus obtained, the X-direction straight line generator generate an increment signal of zero or integer for each of the X-and Y- directions (zero or +l or -l in this embodiment).
  • the Y-direction straight line generator l4 will operate, when there is to be determined a position on a destination coordinate of a next dot adjacent to a just before coordinate-transformed dot in a Y-direction line on the source coordinate, to calculate a difference in X- and Y- directions between the destination coordinate position of the just before coordinate-transformed dot and the destination coordinate position of the next dot to be coordinate-transformed, in accordance with a required rotational angle ⁇ and on the basis of the difference on the source coordinate between the just before coordinate-­transformed dot and the next dot to be coordinate-­transformed.
  • the Y-direction straight line generator generate an increment signal of zero or integer for each of the X-and Y-­directions (zero or +l or -l in this embodiment).
  • These X-­and Y- direction straight line generators are well known in the art, and therefore, further explanation will be omitted.
  • ⁇ X and ⁇ Y are a set of integers fulfiling such a relation that ⁇ X/ ⁇ Y is perfectly or substantially equal to tan ⁇ (where ⁇ is a required rotational angle).
  • the X-direction straight line generator l2 operates to receive, as an initial value, the destination coordinate position of a leading dot of the rotated pattern, which is outputted from the processing apparatus l0. In addition, the X-direction straight line generator l2 reads the integer values ⁇ X and ⁇ Y held in the registers l6 and l8.
  • the pair of increment signals XD X and YD X are inputted to an adder 20 and an AND circuit 22.
  • the Y-direction straight line generator l4 also receives, as initial value, the destination coordinate position of a leading dot of the rotated pattern, which is outputted from the processing apparatus l0. In addition, the Y-direction straight line generator l4 reads the integer values ⁇ X and ⁇ Y held in the registers l6 and l8.
  • the generator l4 On the basis of these input data, the generator l4 generates a pair of increment signals XD Y and YD Y representative of difference ⁇ XD and ⁇ YD in X- and Y- directions on the destination coordinate corresponding to the difference between the leading dot of the just before coordinate-transformed X-direction line and the leading dot of an adjacent X-direction line to be coordinate-transformed next. Namely, the generator l4 provides coordinate transformation information for coordinate rotation of a straight line connecting the leading dots of all the X-­direction lines L K on the source coordinate.
  • the system also includes another pair of registers 24 and 26 which receive and hold the destination coordinates XD and YD of the leading dot outputted from the processing apparatus l0 at the initialization stage.
  • the registers 24 and 26 hold the destination coordinates XD and YD inputted from the adder 20.
  • the adder 20 reads the destination coordinates XD and YD from the registers 24 and 26 and adds the input increment signals XD X , YD X , XD Y and YD Y with the designation coordinates XD and YD.
  • the added values are outputted and held in the registers 24 and 26, again. Namely, the registers 24 and 26 are updated each time the generators l2 and l4 generate the increment signals.
  • registers 28, 30, 32 and 34 which are respectively written at an initialization stage by the processing apparatus with the reference dot source coordinate position XS1 and YS1 and the dot lengths DH and DV in X- and Y- directions of a rectangular pattern on the source coordinate to be rotated, respectively.
  • the data held in these registers 28 to 34 are read by the processing apparatus l0.
  • Registers 36, 38, 40 and 42 are associated to the registers 24, 26, 28 and 32, respectively, for reserving the data held in the respective registers.
  • the AND circuit 22 has an output connected to a dot generator 44.
  • the dot generator 44 reads the data XD from the register 24 and then writes a l-substracted data XD-l to the register 24.
  • the generator 44 generates a control signal instructing to write a dot information stored in a register 46 associated to a display memory 48, to a coordinate position (XD-l, YD). Thereafter, the generator 44 writes the data XD to the register 24, again. Namely, the content of the register 24 is returned from XD-l to XD.
  • the system also includes a drawer 50 which reads the data from the registers 24, 26, 28 and 30 so as to calculate an address of the display memory 48 to which a read/write should be executed.
  • the calculated address is supplied to the display memory 48, so that a dot information is read from the designated address.
  • the read dot information is temporarily held in the register 46.
  • the display memory 48 is controlled by a read/write control signal outputted from the processing apparatus l0. Namely, after a dot information held in the address of the display memory 48 designated by the drawer 50 and corresponding to the position (XS, YS) on the source coordinate is read to and held in the register 46, the dot information held in the register 46 is written to an address of the display memory designated by the drawer 50 corresponding to the position (XD, YD) on the destination coordinate corresponding to the source coordinate position (XS, YS).
  • the display memory 48 is controlled by the control signal generated by the dot generator 44 to write the same dot information as that on the destination coordinate position (XD-l, YD-l), to an address of the display memory corresponding to the position determined by the coordinate position XD-l written to the register 24 from the dot generator 44 and the coordinate position YD held in the register 26.
  • the X- and Y- direction straight line generators l2 and l4 are previously initialized to calculate necessary increments in the coordinate system in accordance with the integer values ⁇ X and ⁇ Y defined by a given rotational angle ⁇ , each time the dot position to be coordinate-transformed is shifted dot by dot on the source coordinate, and the various registers are set with initial values as the result of the initializing operation of the processing apparatus l0.
  • the generators l2 and l4 are inputted with the destination coordinate position (XD1, YD1) from the processing apparatus l0.
  • the coordinate position (XD1, YD1) constitutes a reference point.
  • the registers 24, 26, 28, 30, 32 and 34 are written with data XD1, YD1, XS1, YS1, DH and DV by the processing apparatus l0, respectively.
  • the data XD1, YD1, XS1 and DH are reserved in the registers 36, 38, 40 and 42 (Step A).
  • a dot information (al shown in Figure 3A) corresponding to the source coordinate reference position (XS1, YS1) is read from the display memory 48 and held in the register 46 (Step B).
  • the data YS is incremented by +l (Step C).
  • the dot position (a1 shown in Figure 3C) defined by the destination coordinate position (XD1, YD1) is rewritten with the dot information held in the register 46 (Step D).
  • the X-direction straight line generator l4 is operated to calculate the next draw point (XD, YD) to which a dot (b1 shown in Figure 3A) adjacent to the reference coordinate (XS1 and YS1) in the same line on the source coordinate should be converted (Step E). At this time, it is discriminated whether or not both of XD and YD are incremented (Step F). If both of them are incremented, a dot (all shown in Figure 3C) corresponding to the position (XD-l, YD) is rewritten with the dot information held in the register 46 under the control of the dot generator 44 (Step G). To the contrary, if only the data XD is incremented, the dot generator 44 is not operated.
  • Step H the data DH is decremented by l (i.e., added with -l) (Step H). Then, it is discriminated whether or not the data DH is less than zero (Step I). If DH is equal to or larger than zero, the operation is returned to the step B. Thus, the above mentioned step sequence is repeated on the dots b1, c1, d1, ... until DH becomes less than zero. If DH becomes less than zero, YS is incremented by +l, and at the same time DV is decremented by l (i.e., added with -l) (Step J). Then, it is discriminated whether or not DV is less than zero (Step K). If DV is less than zero, the operation is terminated.
  • l i.e., added with -l
  • Step L the contents of the registers 24, 26, 28 and 32 are returned to the data stored in the registers 36, 38, 40 and 42, respectively.
  • the Y-direction straight line generator l4 is operated to calculate the destination coordinate position (XD2, YD2) of the leading dot (a2 shown in Figure 3C) of the next line L2 (Step M).
  • the data XD2 and YD2 are reserved in the registers 36 and 38 (Step N), and the operation is returned to the step B.
  • Step N the above mentioned operation is repeated until DV becomes less than zero.
  • the shown system can generate a rotated pattern having no dot lack even in the case of a rotational angle not less than 45 degree.
  • a rotated pattern generation system using a pair of straight line generators a pattern added with not only rotation but also inclination can be generated by adjusting the inclination between the two generated straight lines.
  • the present invention can be also applied to this type of rotated pattern generation system. Further, the present invention can be applied to rotation of a non-­rectangular pattern and rotation of a rectangular pattern out of parallel to the X- and Y- axes of the source coordinate. In these cases, however, the processing will become complicated to some extent.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Image Processing (AREA)
  • Controls And Circuits For Display Device (AREA)
  • Image Generation (AREA)
  • Digital Computer Display Output (AREA)
EP87110628A 1986-07-22 1987-07-22 System zur Erzeugung von gedrehten Graphikmustern Withdrawn EP0254300A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP173105/86 1986-07-22
JP61173105A JPH0661103B2 (ja) 1986-07-22 1986-07-22 回転図形生成装置

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EP0254300A2 true EP0254300A2 (de) 1988-01-27
EP0254300A3 EP0254300A3 (de) 1990-05-16

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EP (1) EP0254300A3 (de)
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0396311A2 (de) * 1989-04-28 1990-11-07 International Business Machines Corporation Bildverarbeitungsverfahren und -gerät

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5600734A (en) * 1991-10-04 1997-02-04 Fujitsu Limited Electron beam tester
JPH0455986A (ja) * 1990-06-26 1992-02-24 Toshiba Corp 画像処理装置
KR930007023B1 (ko) * 1990-12-31 1993-07-26 삼성전자 주식회사 컴퓨터 그래픽 시스템에서의 화상변환방법 및 그 장치
US5414474A (en) * 1992-03-04 1995-05-09 Fujitsu Limited Moving body recognition apparatus
WO1994010646A1 (en) * 1992-10-30 1994-05-11 Sega Enterprises, Ltd. Image processor
KR970703568A (ko) * 1995-04-07 1997-07-03 이시마루 미키오 영상 회전방법 및 장치(method and apparatus for image potation)
US5664082A (en) * 1995-06-06 1997-09-02 Apple Computer, Inc. Method and apparatus for arbitrary transformation of images
US5901253A (en) * 1996-04-04 1999-05-04 Hewlett-Packard Company Image processing system with image cropping and skew correction
US5956043A (en) * 1997-09-18 1999-09-21 Novell, Inc. Textured tile rotation system and method
US20070216711A1 (en) * 2006-03-14 2007-09-20 Microsoft Corporation Microsoft Patent Group Abstracting transform representations in a graphics API

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0177997A2 (de) * 1984-09-14 1986-04-16 Philips Electronics Uk Limited Verfahren und Apparat zur Verarbeitung von Videosignalen
EP0235471A2 (de) * 1986-02-28 1987-09-09 Digital Equipment Corporation Transformationsschaltung für Rasteroperationen

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3976982A (en) * 1975-05-12 1976-08-24 International Business Machines Corporation Apparatus for image manipulation
US4631750A (en) * 1980-04-11 1986-12-23 Ampex Corporation Method and system for spacially transforming images
JPS58110255A (ja) * 1981-12-25 1983-06-30 Hitachi Ltd プリンタ制御装置
JPS6188374A (ja) * 1984-10-08 1986-05-06 Hitachi Ltd 画像デ−タ回転処理装置
JPS62237581A (ja) * 1986-04-09 1987-10-17 Hitachi Ltd 画像処理装置
JPH0679335B2 (ja) * 1986-06-13 1994-10-05 富士ゼロックス株式会社 画像回転装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0177997A2 (de) * 1984-09-14 1986-04-16 Philips Electronics Uk Limited Verfahren und Apparat zur Verarbeitung von Videosignalen
EP0235471A2 (de) * 1986-02-28 1987-09-09 Digital Equipment Corporation Transformationsschaltung für Rasteroperationen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
COMPUTER GRAPHICS & IMAGE PROCESSING, vol. 13, no. 2, June 1980, pages 127-141, Academic Press, Inc., New York, US; C. BRACCINI et al.: "Fast geometrical manipulations of digital images" *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0396311A2 (de) * 1989-04-28 1990-11-07 International Business Machines Corporation Bildverarbeitungsverfahren und -gerät
EP0396311A3 (de) * 1989-04-28 1992-12-16 International Business Machines Corporation Bildverarbeitungsverfahren und -gerät

Also Published As

Publication number Publication date
EP0254300A3 (de) 1990-05-16
US4930088A (en) 1990-05-29
JPS6327983A (ja) 1988-02-05
JPH0661103B2 (ja) 1994-08-10

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